1. Field of the Invention
The present invention generally relates to Light Emitting Diode (LED) arrays, and more specifically to a method and apparatus for increasing reliability of operation of the LED arrays in lamps operating at higher temperatures. The invention also relates to the use of such lamps as brake/tail lamps of an automobile.
2. Related Art
A light emitting diode (LED) commonly contains a semiconductor p-n junction, and produces light with an intensity directly proportional to an electric current flowing through it in the forward direction. Many of such LEDs are often formed as an array, commonly to generate light of a desired level of intensity.
LED arrays may in turn be packaged as lamps along with other components such as driver circuits and casings. One such application is the use of LED array based lamps as brake and tail lamps in automobiles. In general, the brake light generates light of one intensity in response to brake being applied, and a tail lamp generates light of another intensity especially during night.
One problem with LED array based lamps is that the LED arrays may be susceptible to failures at high operating temperatures (i.e., in the general surroundings of the light or automobile). The source of such failures is often that the operating temperature may cause an increase in the temperature of P-N junctions in the LEDs, thereby further increasing the temperature in the immediate viscinity of the LED arrays, which could destroy/burn the LED material (including the P-N junction, casing, or wire-bonding of the PN junction to connecting leads).
What is therefore needed is a method and apparatus for increasing the reliability of operation of the LED arrays in lamps operating at higher temperatures.
In the drawings, like reference numbers generally indicate identical, functionally similar, and/or structurally similar elements. The drawing in which an element first appears is indicated by the leftmost digit(s) in the corresponding reference number.